Impulse sending device



7 April 16, 1929. H. F. OBERGFELL IMPULSE SENDING DEVICE Original Filed Deg. 10, 1923 I H arbFr f fi beggiall' fi Zwaw Patented Apr. 16, 1929.

* UNITED STATES PATENT OFFICE- HERBERT 15. OBERGFELL, '0]? RIVER FOREST, ILLINO S, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO AUTOMATIC ELEOTRIC INC OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

IMPULSE snivniive DEVICE.

Original applicationv filed December 10, 1923, Serial No. 679,517. Divided and this application filed August My invention relates in general to impulse sending devices of the dial type in which the impulses are generated and transmitted in definite series corresponding to definite digits by successive manipulations of the dial.

More particularly, the invention relates to devices of the above type in which the action of the impulse mechanism is automatically controlled by a governor, and the impulses are generated by the action of an interrupter, commonly and hereinafter termed the impulse cam, which latter as well as its governor are driven from the dial by means of appropriate gear transmission; In these devices, and particularly when, as in the present instance, they are constructed in the form ofa calling device for automatic telephone systems, many efforts havebeen made and various means devised to prevent sticking and reduce binding and abrasion between gears.

The principal object of the invention is to provide an improved mechanism for accomplishing the above results. I have discovered that by the use of a laminated. worm gear consisting of a blank or layer of black fibre, or other suitable oil holding material, held between two phosphor bronze flanges or disks, I am able to practically en tirely eliminate sticking and to reduce binding and abrasion to nil for all practical pur poses. 1

Other'new and improved features in the governor mechanism include a new and improved type spring in which the material used is phosphor bronze, and the design used in fasteningit to the Worm shaft isnew and improved, thus eliminating the previously used aluminum hub and practically eliminating breakage; anew and improved type of governor fly-ball in which a piece of'a gray fibre rod, or other suitable bearing material, is rounded oif and inserted in the fly-balls to serve as a friction shoe and thus reduce abra Serial N 0. 53,039.

pitting or breaking down of the bearing surface. i

The present application is a division of pending application, Serial N 0. 679,517, filed December 10, 1.923, and features of novelty disclosed, but not claimed are covered by the original application referred to.

The above important featuresof the invention and other details will now be more fully described in the specification which is to follow, reference being had to the accompanying drawing, in which Fig. l is a front view of the device; Fig. 2 is a side view of the same, looking in the direction of the arrow'in Fig. 1, with one of the mounting lugs broken away for clearness; Fig. 3 is a rear view of the same; Fig. 4. is a perspectiveview of the telephone number and letter dial instruction of designation card, and dial escutcheon and escutcheon plate or adapter for same; Fig. -5 is, an axial section of the governor mechanism taken on the line VV of Fig; 2; Fig. 6 is a perspective view of the coil main spring hub or support, and the shunt spring controlling lever; Fig. 7 is a perspective view of the laminated worm. gear and pinion assembly; Fig. 8 is a view of the spring 26 on line AA of Fig. 5;'w'hil e Fig. 9 is a perspective View of the spring 26.

The impulse sending device illustrated comprises the usual finger hold dial 2 (as shown in Figs. 1 and 2) pivoted at a central point'in the base plate3 (Figs. 1, 2 and 3) by means of a rod and having a coil main spring 4, one end of which is fastened to the rod or pin 5 to which the finger holddial is fastened and which acts as a pivot for said dial, and the other end of which is fastened to a lug G on'the under side of the base plate 3. The spring t acts to return the finger hold dial 2 to its normal position after thespring has been wound up by the rotation of the dial in a clockwise direction. A gear wheel is mounted loosely upon the pivot rod 5 between the dial and the plate 3, as shown, for exainple, in U. S. Letters Patent No. 1,461.,944to Setter, dated July 17, 1923, which wheel has gear teeth around its circumference and also has ratchet teeth out in its face lying adjacent to the dial 2. These ratchet teeth are spaced apart the same angulardistance as the holes in the finger dial. Through an .60 bronze spring 26 is tightly fitted. The

1 opening in the dial 2 is placed a small metal dog which co-operates'with the ratchet teeth on thegear wheel to :rotate the latter with the fin er hold dial in its return or counterclockwlse motion only until the dial reaches normal. 1 i

Co o erating with the gear teeth in the clrcum erence of the gear wheel upon the pivot rod 5 is a pinion 7 (Figs. 2 and 7 fixed to a shaft which is pivoted to the bracket 8 Figs. 2 and3) at one end and in an oil set part of base plate 3 at the other end. Mounted on this same shaft is a laminated worm, gear wheel 9, which will be explained later, and a cam 10, shown in Figs. 2 and 3,

' having two'wings adapted, when the shaft is rotated, to open and close contact of a pair of springs 11 and 12, which are usually used to send impulses over the well known two wires of a telephone system to control automatic switches.

' the wheel becomes held more secure as it is driven on. The projecting shoulder is then staked to hold the wheel in position.

. 3,*which drives" the Teeth are then out on thebias to mesh with the governor worm 13, as best shown in Fig. governor in the usual well known manner. r

The governor consists of the hardened steel-worm shaft 13, as best shown in Fig.

l 5, which shaft is knurled to cause a tight (it of the round brass hub 20. The shaft is also fiattened atitsendsand polished to bear 7 against the hardened and polished chrome steelball bearings 21 and 22. The ball beari ing 21 receives very little wear and hence race 24, which is held stationary.

is merely driven tightly in place, while ball bearing 22 receives a thrust when the worm shaftis rotated and is thereforearranged as follows: In the screw end of the governor cup 23 is a hardened steel polished concave The ball bearing 22 is smaller than the bore of the screw end of the "governor cup and is held loosely in place by the ground brass bushing-"25 which is held stationary and has its bearing end slightly bent into a diameter less thanthat of the steel ball. The spring 26-is formed from a perforated'blank having ample material surrounding the perforation to, by a drawing process, form acup-like structure. The hub .20 has a collar at one endover which the cup of the phosphor spring-is further held by prong staking or V riveting the collar of the hub which extends slightly beyond it, while the hub is further r tightenedto the shaft by ring staking the end opposite the collar. To the ends of the governor spring 26 are riveted round brass governor fiy-balls 27 and 28. These fly-balls are drilled out and in them are inserted conical shaped fibre friction shoes 29 and 30 which have their tops cut off and rounded, and are held securely in place by ring shoulder staking.

Three springs, 14, 15, and 16, as shown in Figs. 2 and 3, are provided and are what is known as the shunt springs; that is, these springs are allowed to close by bushing 17 as soon as the calling device leaves its normal position and are used to shunt the talking equipment at a subscribers station in the usual well known manner. The bushing 17 is held on the end of: the hard sheet brass shunt spring lever 18, as shown in Figs. 2. 3,

and 6, by nicking the latter. The lever 18. (Fig. 6-), fits over the collar on the top end of the hub 19, after the end of the main spring 4 has been placed in the groove which extends slightl 1 below said collar, its inner projections fitting in said groove thus holding the main spring in place and ke'epinv the hub from turning with respect to it. The to of the collar is then curled over or rivete to hold the lever securely in plam.

The hub 19 is of sufficient. length to almost touch against the stationary hub (not shown) of the base plate 3, which hold the rod or pin 5, and thus limits the distance the dial 2 can be pulled out with the spring in place. The bottom end of the hub is tapered so as to accommodate the decreasing diameter at the middle of. the coil spring 4 as it is wound up or tensioned.

A dial instruction card 38, as best shown in Fig.1, is mounted on the face of the dial 2 as follows: The dial eseutcheon plate or adapter 31, as shown in Fig. 4, is made from soft sheet brass, or other suitable material, and has its edge turned over so as to rest socurely on the face of the dial. It has a lowcred bearing surface 32 and a lowered screw hole 33, the surface leading down to the latter being shaped to accommodate the head of the screw 37, which screw. fastens the plate to the dial. The plate further has a projection 84 which fits into the hole 50 of the dial and holds it from turning, and cut out portions 35 and 36 to function with the dial escutcheon or coverring 41 as will be explained later.

The dial instruction card 38, made of white index bristol, or other suitable material, lies on top of the escutcheon plate 31 and has a projection 39 to function with the cover ring 41 as will also be explained later. The transparent celluloid cover 40 lies on top of the instruction card 38 and both are covered and held in place by the ring 41. The ring 41 is made from soft sheet brass, or other suitable material, and has its edge turned ovuto fit the escutcheon plate 31, the slight pmjections 42 and 43 being bent in to map unto place and mesh with the out out portions 35 and 36, respectively, of the plate 31. i The cut out portion 44 accommodates the projection 39 of the card 38 and keeps the card from turning as well as positions it with respect to the dial.

lhe operation of the device is as follows: ln the well known manner the user of the device places his finger in the hole, through which can be seen the desired digit, of the finger hold dial 2, and pulls the dial around in a clock-wise direction until the finger has encountered. the stop 51, shown in Figs. 1, 2 and 3, at which time the finger is withdrawn. As previously pointed out, the associated gears do not move during this operation, but tension is stored in the main coil spring 4c, and the shunt springs are closed by the movement of lever 18. "When the finger is withdrawn the spring 4 exerts a force upon the dialQ and rotates same back towards its normal position,

causing the associated gear wheel (not shown) and pinion 7 to rotate with it. The snatt of pinion 7 tl'ierehy rotates the cam 10 to cause the springs 11 and 12 to be separated momentarily a number of times corresponding to the number of the linger hole into which the users linger was inserted, and rotales the laminated worm wheel 9 to cause the governor to regulate thespeed of rotation ol the parts in returning to normal. When the laminated worm wheel 9 is rotated it gives a rotating thrust to the worm shaft 13 due to its biased teeth. This rotating thrust causes the chrome steel. hall 22 to be pressed against the steel concave race 9A and become autodiameter of said huh drawn into the form of a cup and fitting over said huh with said wings extending alon said huh.

2. In a governor, a shaft, a spring perforated at its mid point, a huh on said shaft having a reduced portion adapted to register with the hole in said spring, said. spring having a substantial amount of material forming a cup fitting over a portion o't said huh andhaving extensions, and speed controlling weights mounted at the ends thereof.

3. In a governor, a pair of springs formed from a single piece of metal, said piece of metal comprising a strip of phosphor bronze peri'orated at its mid point with the material imn'iediately surrounding the perforation formed into the form of the cup and with sectional eontiiniations of the walls of the cup serving as said springs.

lln witness whereof, I hereunto subscribe my name this 26th day of August A. 1)., 1925.

,lR-RERT F. OBERGFELL. 

